Rotary brush



April 18, 1961 BENYAK 2,979,749

ROTARY BRUSH Filed July 11, 1958 INVENTOR. JOHN B. BENYAK 0M0 ofmMATTORNEYS United States PatetitO ROTARY BRUSH John B. Benyalr, Parma,Ohio, assignor to The Osborn Manufacturing Company, Cleveland, Ohio, acorporation of Ohio .7

Filed July 11, 1958, Ser. No. 748,032

4 Claims. (Cl. 15-179) This invention relates as indicated to a novelrotary brush, and more particularly to a special form of power drivenrotary brushing tool in which tufts of brushing material are mounted andarranged to afiord a relatively narrow but dense brush face.

Reference may be had to my prior co-pending Patent No. 2,844,835, forTufted Brush Construction, of which this application is acontinuation-in-part. In such prior application, I disclose a form oftufted power driven rotary brush in which the tufts are flattened andarranged to produce a relatively narrow and dense brush facecircumferentially of the tool. This brush is very advantageous forcertain purposes where it is desired to brush narrow slots and grooves,but there is nevertheless a tendency for individual bristles to becaught and bent laterally of the brush where they may mar adjoiningsurfaces and eventually break off. The brushing of such regions aspiston ring slots in automotive engine pistons requires not only thatthe brushing tool have a relatively narrow brush face with the action ofthe brush material under complete control, but also that such brush facebe laterally flexible to accommodate slightly diagonal engagement of thetool into the angles of such slots, etc. Where the slots areexceptionally deep, it is also important that the brushing tool be ofnarrow crosssection even in regions spaced substantially radiallyinwardly from the brush face itself.

' In view of the foregoing, it is a principal object of my invention toprovide a novel rotary brushing tool which will have a very narrow brushface adapted to'enter slots and the like in work-pieces and in which thebrush material'will be under complete control while neverthelesspreserving a substantial degree of lateral flexibility;

Another-object is toprovide such rotary brush capable of automatic orsemiautomatic manufacture to produce a ,well-balanced tool having brushmaterial uniformly distributed circumferentially thereof.

1 A further, object is to provide such rotary tool which may be of verynarrow cross section throughout and not merely at the brush face.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said inventionthen comprises the features hereinafter'fully described and particularlypointed out in the claims, the following description and the annexeddrawiir'g setting forth'in detail certain illustrative embodiments of.the invention, these being indicative, however, of but a few of thevarious ways in which the principle of the invention may be employed.

"f'ln; said annexed drawing: l'is a semi diagrammatic view showing aplurality Fig. 3 is a transverse cross-section on an enlarged scaletaken on the line 33 on Fig. 2;

Fig. 4 is an axial end view of one form of my new rotary brushing toolpartly broken away to disclose the internal construction thereof;

Fig. 5 is an enlarged transverse cross-section taken on the line 5-5 onFig. 4;

Fig. 6 is a fragmentary axial view of a rotary tool constituting apreferred embodiment of my invention;- and Fig. 7 is a transversecross-section taken on the line 7-7 on Fig. 6.

Fig. l of the drawing shows in a semi-diagrammatic manner threerotarybrushes 1, 2 and 3 in accordance with my invention mounted upon an arbor4 and properly spaced apart by interposed tubular spacers to engage maybe mounted on a brush arbor or mandrel.

against all wear and'abrasion at this point.

within corresponding grooves 5, 6 and 7 of an automotive engine piston8. Such piston will be rotated on its longitudinal axis for completecircumferential coverage of such slots by the brushing tools and thepiston may also be reciprocated slightly during engagement with suchtools to ensure complete uniform brushing of the grooves.

As shown in Figs. 2-5 inclusive, the brushing tool of this invention maycomprise a central steel disc 9 adapted to serve as a hub and having acentral aperture 10 which A num ber of small apertures 11 arecircumferentially disposed closely within the outer periphery of disc 9,their edges being bevelled or rounded. Through each of such apertures isinserted a tubular sleeve 12, ordinarily of metal, having brush bristlematerial 13 extending therethrough and protruding therefrom in the formof individual tufts. Such bundles of bristles substantially fill thetubes 12 which are rebent after insertion through aper-l tures 1-1 sothat the two tufts protruding from the respective'ends of each tubeextend generally radially outwardly from the disc-shaped hub 9. Theouter ends 14 of the tubes may be crimped or compressed together both toassist in securing the bristle material therewithin and also to form thetufts into relatively thin flat fan-shaped form. When arranged asillustrated, such tufts obviously afiord a relatively dense but verynarrow brush face in substantially the same plane as that of disc 9.

The individual bristles will ordinarily be relatively straight(althoughthey may be slightly crimped on occasion if desired) and willalso ordinarily be fairly long in their extent from the ends of tubes 12to the outer cir cumferential working face of the brush. The bristlesare protected where they pass through the disc, being in ef-' fectenclosed within a hinge member guarding them For this reason, togetherwith the provision of elastomeric enclosing and supporting materialutilized therewith as ex-' plained below, it is feasible to employrelatively hard brush bristle material, even including steel wire havnga Knoop hardness of 600 or more without danger of an excessive amount oflong fracture in use- Such brushes naturally have a much enhancedcutting action. 7 v

- 'Elastomeric material 15 may be molded to enclose the brush material13 and also such tubular holders 12 as shown in Figs. 4 and 5 of thedrawing. When thus molding the elastomeric material such as spongeNeoprene,

of my new brushing tools mounted upon an arbor and spaced simultaneouslyto engage corresponding piston ring slots "in an automobile enginepiston;

f Fig. :2 ha fragmentary axial view of a rotary brush element adapted tobe utilized in accordance with m invention-"to "produce my improvedbrushing tool;

thin flatout'eicircumferential portion 16 0f. the composite tool'inay'be" flexed laterally'in use as may befiquired',"

Patented Apr. 18, 1961.

a 3 and the outer end portions of the brush bristles may also bendcircumferentially of the tool to the extent resiliently yieldinglypermitted by the elastomeric material.

A preferred embodiment of my invention is shown in Figs. '6 and'7 of thedrawing, affording a brushing .tool of particularly thin cross-section.In such embodiment, a central sheet metal disc 17 is employed having acentral aperture 18 adapted for mounting upon an appropriate mandrel orbrush arbor. Instead of providing a plurality of tuft securing apertures11 adjacent the outer periphery of the disc, however, I provide notcheshaving arcuate portions 19 of more than 180 at their inner ends andstraight-sided slotted portions 20 extending therefrom to the outerperiphery of disc 17. Then, instead of providing double tufts of brushbristle material protruding from the respective ends of the U-shapedsleeve members 12, I employ single tufts 21 of brush material, the innerends of the tufts being held in retaining tubes 22. The outer ends ofsuch tubes are crimped or flattened and flared as at 23 to form thetufts into thin fan form. The opposite ends 24 of the tubular holders 22are likewise flared, although ordinarily to a less degree, in order thatsuch flared ends 24 may act as locking means when the tubes 22 arefitted in slots 20 with such flared inner end portions spreadingflatwise within the wider arcuate inner portions 19 of the radiallydisposed notches. Adhesives and like bonding means may be providedwithin the tubes 22 to assist in retaining the bristles. Such tubes andthe bristles themselves are, however, further secured againstdisplacement by molding an appropriate elastomer 25 such as spongeNeoprene to enclose the entire assembly (although the radially innerportion of disc 17 may remain exposed if desired). Since but a singlefan-shaped tuft emerges from each tubular holder 22 (in contrast to theFig. 3 embodiment), the elastomeric material may be intruded between thebristles, and the whole compressed to form an extremely thin laterallyflexible, radially outer portion 26 as shown in Fig. 7. Furthermore,inas much as the tubes 22 lie generally in the plane of disc 17 and neednot be of appreciably greater thickness than such disc, the entire toolmay be of much more narrow cross-section (in contrast to the Fig.embodiment) and is accordingly adapted to be inserted into narrow slotsand the like not previously adapted to power brushing.

It will thus be seen that I have achieved the several objectives of myinvention by providing a high speed power driven rotary brushing toolhaving an exceptionally narrow brush face adapted to be inserted intoquite deep slots and the like. Such thin layer of brush material issupported for more effective engagement with'the work While at the sametime reducing danger of damage to the brush material itself. Thebrushing tool is so thin in cross-section that it is laterally flexibleto a substantial degree despite the employment of elastomeric materialintruded therewithin and bonded thereto. The metal parts of the brushassembly may desirably be provided with a thin coating of an epoxy resincomposition effective better to bond the elastomeric material thereto.Of'course;

a wide variety of such elastomeric materials may be utilized dependingupon the particular operation Where the 7 tool is to be employed.

In the Figs. 4 and 5 embodiment of the invention it will be apparentthat the tubular Ushape holders 12 may be capable of a small amount ofpivotal or swiveling movement in apertures 11 even when the elastomeric.material has been molded thereover, particularly when but a thin layerof the elastomer is employed. In the Figs. 6 and 7 embodiment, however,the tubular holders 22 are rigidly held against movement relative to thedisc in a circumferential direction although a small amountoflatoral-movement may be afiorded. The elastomeric material not-onlyassists in supporting the brush bristles but also 4 elastomeric materiallikewise assists in resiliently maintaining the tubular brush materialholders properly oriented and protects both the work and the hubpartsfrom damage resulting from accidental contact in use.

A wide variety of brush material may be employed, including low dampingcapacity steel wire having a Knoop hardness of 600 or more, glassfilaments, nylon coated wire filaments, tampico fiber and fabric buffmaterial.

The elastomeric material should ordinarly be able to withstandreasonably high operating temperatures without softening or smearing thework. Examples include: Rubber (if operating temperatures are not toohigh) Neoprene (polychloroprene) Hycar (modified copolymers of butadieneand acrylonitrile) Nylon (polyamide resins) Vinyl plastics (vinylpolymers and copolymers) Melamine resins (melamine-formaldehyde reactionproducts) It is often advantageous to utilize a thin coating of anappropriate adhesive such as epoxy resin composition adhesives to assistin bonding the elastomeric material to the brush material, particularlywire. Abrasives such as alum'num oxide and silicon carbide may beincorporated in the elastomeric material and also certain fillermaterials such as bentonite and whiting to render the elastomericmaterial somewhat more readily erodable at the brushing face of the toolso that such elastomeric material may erode back in use at a greaterrate than the brush bristle material, with the result that the latterwill protrude sl ghtly therefrom at all times eventhough the elastomericmaterial may initially extend to the brush face prior to use. An exampleof a suitable elastomeric composition for employment as the resilientbody'is as follows:

When heated in an appropriately, formed mold with the brush assembly,such elastomeric material composition is softened and intruded betweenthe bristles under the action of the blowing agent, and upon furtherheating and curing a resiliently flex'ble and deformable spongedelastomeric body is formed. Reference may be had to the co-pendingapplication of Ruben 0. Peterson Serial No. 686,499, filed September 26,1957, for Composite Brushing Tool for a more detailed description ofsuitable materials comprising the elastomeric body.

Other modesof applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I therefore particularly point out and distinctly claim as my invention:

1. A rotary brush comprising a disc-shaped hub having a large number ofgenerally radially inwardly extending notches in its outer peripheraledge, such notches being wider in their radially inner end portions thanadjacent such edge to afford relatively narrow necks thereto, a brushmaterial retaining tube inserted in each such notch in a radialdirection closely fi ng s ch neck and. having their inner -end portionsco pr s d and generally in the plane of such disc to provide a dovetailkey securing them against radially outward withdrawal from said notches,brush material secured in each said tube and extend'ng outwardlytherefrom in a thin layer generally in the plane of said disc to form athin circular brush face, said tubes being compressed and flared intheir outer end portions to spread said brush material into thinfan-shaped layers thus to form such brush face, and elastomeric materialintruded between said bristles slightly to space them apart, sadelastomeric material being molded to form with said bristles a thinlaterally flexible blade-like outer peripheral portion adapted to beinserted into slots in work-pieces, wherein said elastomeric materialextends radially inwardly to enclose said notches and tubes.

2. A rotary brush comprising a disc-shaped hub having a large number ofgenerally radially inwardly extending notches in its outer peripheraledge, such notches being wider in their radially inner end portons thanadjacent such edge to aflord relatively narrow necks thereto, a brushmaterial retaining tube inserted in each such notch in a radialdirection closely fitting such necks and having their inner end portionscompressed and flared generally in the plane of such disc to provide adovetail key securing them against radially outward withdrawal from saidnotches, brush material secured in each said tube and extendingoutwardly therefrom in a thin layer generally in the plane of said discto form a thin circular brush face, said tubes being compressed andflared in their outer end port'ons to spread said brush material intothin fan-shaped layers thus to form such brush face, and elastomericmaterial intruded between said bristles slightly to space them apart,said elastomeric material being molded to form with said bristles a thinlaterally flexible blade-like outer peripheral portion adapted to beinserted into slots in work-pieces, wherein said elastomeric materialextends radially inwardly to enclose said notches and tubes, and saidelastomeric material is a sponge Neoprene composition adapted to erodeaway at the work face in use slightly more rapidly than the brushmaterial wears back.

3. A rotary brush comprising a disc-shaped hub having a large number ofgenerally radially inwardly extending notches in its outer peripheraledge, such notches being wider in their radially inner end portions thanadjacent such edge to afford relatively narrow neck:

thereto, a brush material retaining tube inserted in each such notch ina radial drection closely fitting such necks and having their inner endportions compressed and flared generally in the plane of such disc toprovide a dovetail key securing them against radially outward withdrawalfrom said notches, brush material secured in each said tube andextending outwardly therefrom in a thin layer generally in the plane ofsaid disc to form a thin circular brush face, said tubes beingcompressed and flared in their outer end portions to spread, said brushmaterial into thin fan-shaped layers thus to form such brush face, andelastomeric material intruded between sad bristles slightly to spacethem apart, said elastomeric material being molded to form with saidbristles a thin laterally flexible blade-like outer peripheral portionadapted to be inserted into slots in work-pieces, wherein said brushmaterial is hard steel wire, and said elastomerIc material is a spongeNeoprene composition adapted to erode away at the work face in useslightly more rapidly than said bristles wear back, said elastomeric'material extending substantially from such work face radially inwardlyto enclose said notches and tubes.

4. In a rotary brush having a disc-shaped hub adapted to be mounted onan arbor or the like, said hub having a plurality of dovetail notches inits outer peripheral edge, brush elements secured in said notchescomprising brush material holders fitting in said notches having flaringinner end portions etfective to resist the eflect of centrifugal forcein use, and a single flat tuft of brush material secured in each saidholder and lying generally in the plane of said disc, includingelastomeric material intruded into said brush material to form therewitha thin peripheral portion of said brush, said elastomeric materialextend ng radially inwardly to enclose said notches and holders.

References Cited in the file of this patent UNITED STATES PATENTS1,475,074 McLaughlin Nov. 20, 1923 2,648,084 Swart Aug. 11, 19532,826,776 Peterson Mar. 18, 1958 2,844,835 Benyak July 29, 1958 FOREIGNPATENTS 523,850 Great Britain July 24, 1940 537,303 France May 20, 1922

